Service Instruction Note

Transcription

1 Service Instruction Note DIESEL DIESEL NOV 2000 Based on UK DT271 (EN) SIN 494 All Diesel Fuel Injection Equipment EQUIPMENT: SUBJECT: All Diesel Fuel Injection Equipment The use of different fuel types 1. INTRODUCTION This service instruction note provides information on the various fuel types available for use in diesel engines and their possible effects on the fuel injection equipment. This note also includes details to assist in resolving warranty disputes relating to damage attributed to the use of these fuels. 2. FUEL TYPES Listed below are the current fuel types that this note covers. a) Diesel mineral derived hydrocarbon fuels to European standard EN590 or equivalent. b) Low Sulphur Diesel mineral derived hydrocarbon fuels to EN590 or equivalent. This fuel has totally replaced automotive (road use) diesel in the European union since October 1996 and has sulphur limited to a maximum of 0.05% by weight. c) Ultra Low Sulphur Diesel Reformulated mineral derived hydrocarbon fuels to EN590 or equivalent. Now widely available in UK, mainland Europe & some parts of the USA. Sulphur limited to a maximum of 0.005% by weight or lower. d) Vegetable Oil unmodified. Certain pure vegetable oils (sunflower oil, rapeseed oil etc.) e) Bio Diesel chemically modified vegetable oil. By chemically modifying vegetable oils, methyl esters of that oil are produced. These are collectively known as Fatty Acid Methyl Esters (FAME) or Vegetable Oil Methyl Esters (VOME). 3. USAGE AND EFFECTS OF FUELS Any fuel purchased for use within diesel engines fitted with Delphi fuel injection equipment must be purchased from reputable oil producers / outlets and stored in accordance with the manufacturers recommendations. Delphi Diesel Aftermarket 1624 Meijer Drive Troy, Michigan USA Tel; [1] Fax: [1]

2 SIN 494- Nov 00-2 of Low Sulphur Diesel In its basic form, because of the process of reducing sulphur by removal of sulphur containing compounds (which contribute to mechanical lubrication) an increase in the wear rate of the fuel injection equipment could occur. In view of this, the major fuel producers add suitable lubricity improvers to enable the FIE to run satisfactorily, with no acceleration in wear rate. They must ensure that the lubricity improvers do not themselves create residual deposits that could block the fuel system e.g. filter, injectors etc. In addition to the lubrication effect there can also be a further reduction in the aromatic content of the fuel which can lead to shrinking / cracking of traditionally used nitrile rubber seals throughout the fuel injection equipment that has previously been exposed to higher sulphur level fuels. The major fuel producers tend to maintain the total aromatic content to an acceptable level (15% by volume). 3.2 Ultra Low Sulphur Diesel Also known as city diesel, available throughout the UK and some parts of Europe since March This fuel has a maximum sulphur content of 0.005% by weight and a further reduction in the natural lubricity and aromatic content than experienced with low sulphur diesel. Major oil producers will add lubrication improvers and also maintain the total aromatic content to an acceptable level. 3.3 Unmodified Vegetable Oils Burned in diesel engines neat or used as an extender to mineral derived fuel. When these are subjected to heat in the fuel injection system they form sticky deposits that can be found inside the fuel pump and a hard lacquer in the injectors where exposure to even higher temperatures takes place. 3.4 Chemically Modified Vegetable Oils (FAME / VOME) These fuels have been derived from a wide range of vegetable oils and animal fats, resulting in better stability, viscosity and cetane number than those produced from unmodified vegetable oils, but it is recognised that there are potential problems associated with the finished fuel characteristics. These fuels are less stable than mineral oil derived fuels when stored and they will readily degrade producing fatty acids, methanol and water, none of which are desirable in the FIE. These effects are known to be accelerated when the fuel is stored in the presence of air and water together. The FIE manufacturers Common Statement on the use of FAME fuel and a table of characteristics associated with poor fuel and potential failure modes can be found in appendix 1 and table 1. The three most common FAME types are RME Rapeseed methyl ester (preferred crop in Europe), SME Sunflower methyl ester (preferred crop in southern Europe) and SOME Soybean methyl ester (preferred crop in USA). Less common FAME s can be derived from animal fats (e.g. modified beef extracts) and reclaimed cooking oils.

3 SIN 494- Nov 00-3 of 7 4. TYPICALLY ENCOUNTERED FUELS Below is a list of typically encountered fuels that have been assessed by Delphi Diesel Systems as to their acceptability for use with Delphi fuel injection equipment. Types that appear on the same line are considered to be equivalents. They are divided into 4 groups as follows: - Group 1 Fuel specifications that are considered totally acceptable EN590 Diesel fuel types Auto/C0/C1/C2/C3/C4. French EN590 (RME5) with 5% maximum RME content blended with mineral derived diesel. BS2869 Class A2. ASTM D Class 2, US DF1, US DF2, US DFA. JIS K2204 (1992) Grades 1, 2, 3 and Special Grade 3. Low sulphur / Low aromatic fuel to EN590 with appropriate lubricity additives and acceptable total aromatic content. Ultra low sulphur diesels to EN590 with appropriate lubricity additives and acceptable total aromatic content. Up to 5% FAME / VOME as an extender to fuels in this group. Group 2 Fuel specifications that are considered acceptable against warranty but may lead to reduced service life. ASTM D Class 1DA. MIL T38219 XF63. NATO F63. Group 3 Fuel specifications that will lead to a reduced product life. These are kerosene based and are only acceptable with the use of appropriate additives. Without additives these are NOT acceptable (Fuel supplier / equipment manufacturer will advise on appropriate additive). AVTURFSII, NATO F34, JP8, MIL T83133, DERD 2463, DEF STAN AVCAT FSII, NATO F44, JP5, MIL T5624, DERD 2452, AVTOR. NATO F35, JET A1, DEF STAN 91-91, DERD 2494, JP7. AVCAT, NATO F43 (obsolete), JP5 without additives. JET A (ASTM D1655). ASTM D3699 Kerosene. Group 4 Fuels considered not acceptable with or without additives. AVTAG (obsolete). AVTAG FSII (obsolete), NATO F40, JP4, DERD JET B (ASTM D1655). BS MA100. JIS K2203 No.2 Unmodified vegetable oils. 5. SERVICE POLICY 5.1 Warranty on groups 3 and 4 fuels. Delphi Diesel Systems can accept no liability whatsoever for failure of its fuel injection equipment where failure is attributed to fuels that it was not designed to run on and therefore no warranty is given on FIE used with these fuels.

4 SIN 494- Nov 00-4 of Unmodified Vegetable Oils Unmodified vegetable oils. Lucas recommend that neither neat unmodified vegetable oil nor blends of unmodified vegetable oil and mineral derived fuel is used in its fuel injection equipment. To do so will invalidate the warranty, as they were never designed to run on such fuels. 5.3 FAME / VOME Whilst it is recognised that there are potential problems associated with FAME fuels, the presence of FAME is not sufficient to reject warranty. Where the FIE failure can be directly attributed to the quality of the fuel used, associated repairs will be on a chargeable basis whether in or out of the warranty period. 5.4 Examples of Failure Modes The following pictorial evidence illustrates examples that could be found in service and can be used as guidelines for warranty purposes. Fig. 1 Fig. 1a Dark sticky deposits from the use of unmodified vegetable oil or poor quality FAME found on internal components. Action: Ensure ALL contamination is removed and replace affected components on a chargeable basis. Reject warranty. Fig. 2 Fig. 2a

5 SIN 494- Nov 00-5 of 7 Customer complains of poor response requiring linkages to be reset. However, upon inspection zinc plating has been stripped from some internal components e.g. tab washers and throttle shaft attributed to poor quality FAME. Action: Carry out governor related adjustments under warranty if unit is still within warranty period. Ensure no particle contamination exists in FIE and replace affected zinc plated components on a chargeable basis. Fig. 3 Fig. 3a Excessive witness marks on governor thrust sleeve and inner surface of TP liner caused by premature wear that is not attributed to poor quality component manufacturing. Action: Replace worn parts on a chargeable basis. Reject warranty Fig. 4 Nitrile rubber seals have cracked causing fuel leakage. Attributed to fuel attacking the rubber. Action: Ensure no particle contamination exists in FIE and replace affected components on a chargeable basis. Reject Warranty.

6 SIN 494- Nov 00-6 of 7 Table 1 Characteristics associated with poor quality fuel and potential failure modes Fuel Characteristics Effect Failure Mode FAME's (general) Causes some elastomers to soften, swell, Fuel Leakage harden and crack. Free Methanol in FAME Corrodes aluminum and zinc. Corrosion of FIE Low flash point. FAME process chemicals Potassium and sodium compound. Blocked Nozzles Solid particles. Dissolved water in FAME Reversion of FAME to a Fatty Acid Filter plugging Free water in FAME Corrosion Sustains bacteria Corrosion of FIE Sludging Free glycerin, mono & diglycerides in FAME Corrodes non-ferrous metals Sediments on moving parts and lacquering Filter clogging Injector clogging Free Fatty Acid Corrosion of zinc plating Salts of organic acids Organic compound formed Corrosion of FIE Filter plugging Sediment on components High Viscosity at low temperature Generates excessive localized heat Higher stressed components. Pump seizures, early life failures Poor nozzle spray Corrosive acids Corrodes all metallic parts Corrosion of FIE High molecular organic acids Similar to fatty acid, above Polymerization products Deposits in fuel mixes Filter plugging, lacquering formation in hot areas

7 SIN 494- Nov 00-7 of 7 Diesel Fuel Injection Equipment Manufacturers Common Position Statement on Fatty Acid Methyl Ester Fuels as a Replacement or Extender for Diesel Fuels The FIE Manufacturers Position: FIE manufacturers encourage the development of renewable compression ignition fuels. Experience to date with RME fuels in Europe suggests that with fuels conforming to the existing national FAME standards at the point of sale and mixtures with up to 5%vol RME in mineral oil diesel fuel should not give end-users any serious problems. Extending blends to more than 5%vol RME, before suitable standards are developed and agreed, carries a potential risk of reduced product service life and potential fuel injection equipment failure. Even if these fuels meet suitable standards, the enhanced care and attention required to maintain the fuels in vehicle tanks may make for a high risk of non-compliance to the standard during use. Experience with mixtures between 5% and 100% RME and SOME is limited to date but evidence of interaction between the fuels and components in the vehicle low pressure system give the FIE manufacturers particular concern. The fuel injection equipment manufacturers can accept no liability whatsoever for failure attributable to operating their products with fuels for which the products were not designed, and no warranties or representations are made as to the possible effects of running these products with such fuels. Non-compliance of the fuel to standards agreed by the FIE manufacturers, whether being evident by appearance of the known degradation products of these fuels, or their effects within the fuel injection equipment, (see attached list of potential problems) will render the FIE Manufacturers guarantee null & void. The views contained in this Common Position Statement are those of the FIE Manufactures, which comprise of the following: - Robert Bosch GmbH Stanadyne Automotive Corp. LucasVarity plc Signed on behalf of Signed on behalf of Signed on behalf of Robert Bosch GmbH Stanadyne Automotive Corp. LucasVarity plc Mr. K. Krieger Mr. William Kelly Dr. M. Norman Senior Vice President Engineering Vice Pres. & General Mgr. Technical Director Automotive Equipment Group Fuel Injection Pumps LucasVarity Diesel Systems Diesel FIE Division.K5 Diesels Systems Group